What is lung cancer?

Cancer is the uncontrolled growth of cells in the body.  If the cells don't stop growing, they become a mass or lump.  This mass or lump is referred to as a tumor.

If the cells start as lung cells, then their uncontrolled growth is called lung cancer regardless of where they spread in the body.  The type of cell determines the type of cancer.  If the cancer is a type that spreads, it is called malignant.  If it is a type that grows in just one place, the cancer is called benign.